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Biomedical subjects

C Penna

Publications and source records attributed to C Penna.

At least 19 recordsLinked to original sources
PubMed2006

Phytohormone production by three strains of Bradyrhizobium japonicum and possible physiological and technological implications.

The aim of this work was to evaluate phytohormone biosynthesis, siderophores production, and phosphate solubilization in three strains (E109, USDA110, and SEMIA5080) of Bradyrhizobium japonicum, most commonly used for inoculation of soybean and nonlegumes in USA, Canada, and South America. Siderophore production and phosphate solubilization were evaluated in selective culture conditions, which had negative results. Indole-3-acetic acid (IAA), gibberellic acid (GA(3)), and abscisic acid (ABA) production were analyzed by gas chromatography-mass spectrometry (GC-MS). Ethylene and zeatin biosynthesis were determined by GS-flame ionization detection and high-performance liquid chromatography (HPLC-UV), respectively. IAA, zeatin, and GA(3) were found in all three strains; however, their levels were significantly higher (p < 0.01) in SEMIA5080 (3.8 microg ml(-1)), USDA110 (2.5 microg ml(-1)), and E109 (0.87 microg ml(-1)), respectively. ABA biosynthesis was detected only in USDA110 (0.019 microg ml(-1)). Ethylene was found in all three strains, with highest production rate (18.1 ng ml(-1) h(-1)) in E109 cultured in yeast extract mannitol medium plus L-methionine. This is the first report of IAA, GA(3), zeatin, ethylene, and ABA production by B. japonicum in pure cultures, using quantitative physicochemical methodology. The three strains have differential capability to produce the five major phytohormones and this fact may have an important technological implication for inoculant formulation.

Abscisic Acid↗
PubMed2006

Prognosis of stage II colon cancer by non-neoplastic mucosa gene expression profiling.

We have assessed the possibility to build a prognosis predictor (PP), based on non-neoplastic mucosa microarray gene expression measures, for stage II colon cancer patients. Non-neoplastic colonic mucosa mRNA samples from 24 patients (10 with a metachronous metastasis, 14 with no recurrence) were profiled using the Affymetrix HGU133A GeneChip. Patients were repeatedly and randomly divided into 1000 training sets (TSs) of size 16 and validation sets (VS) of size 8. For each TS/VS split, a 70-gene PP, identified on the TS by selecting the 70 most differentially expressed genes and applying diagonal linear discriminant analysis, was used to predict the prognoses of VS patients. Mean prognosis prediction performances of the 70-gene PP were 81.8% for accuracy, 73.0% for sensitivity and 87.1% for specificity. Informative genes suggested branching signal-transduction pathways with possible extensive networks between individual pathways. They also included genes coding for proteins involved in immune surveillance. In conclusion, our study suggests that one can build an accurate PP for stage II colon cancer patients, based on non-neoplastic mucosa microarray gene expression measures.

Adenocarcinoma↗
PubMed2005

Treatment strategy for patients with colorectal cancer and synchronous irresectable liver metastases.

BACKGROUND: The aim of this case-matched study was to determine the best treatment strategy for patients with asymptomatic colorectal cancer and irresectable synchronous liver metastases. METHODS: Between 1997 and 2002, 27 patients with asymptomatic colorectal cancer and irresectable synchronous liver metastases were treated by chemotherapy without initial primary resection (chemotherapy group). These 27 patients were compared with 32 patients matched for age, sex, performance status, primary tumour location, number of liver metastases, nature of irresectable disease and type of chemotherapy, but who were treated initially by resection of primary tumour (resection group). RESULTS: The 2-year actuarial survival rate was 41 per cent in the chemotherapy group and 44 per cent in the resection group (P = 0.753). In the latter group, the mortality and morbidity rates for primary resection were 0 and 19 per cent (six of 32 patients) respectively. In the chemotherapy group, intestinal obstruction related to the primary tumour occurred in four of 27 patients. The mean overall hospital stay was 11 days in the chemotherapy group and 22 days in the resection group (P = 0.003). CONCLUSION: Systemic chemotherapy without resection of the bowel cancer is the option of choice because, for most patients, it is associated with a shorter hospital stay and avoids surgery without a detrimental effect on survival.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2005

[The mesorectum: an anatomical entity that is difficult to evaluate with MRI].

The preoperative assessement by magnetic resonance imaging (MRI) of mesorectum involvement could improve the treatment strategy for patients with rectal cancer. However, the anatomical definition of the mesorectum remains controversial and consequently the accurracy of its analysis by preoperative imaging workup is still unsatisfactory. The aims of this study were to define the mesorectum anatomically and to assess whether it could be evaluated accurately by MRI. Total mesorectal excision was performed in 37 patients with rectal cancer. The mesorectum was inked for anatomical analysis, which was performed before and after fixation in formalin. The mesorectal thickness was measured anteriorly, posteriorly and laterally. Mesorectal involvement was defined by the shortest distance from the outermost part of the tumour to the lateral mesorectal margin. The anatomical measures were compared to those evaluated by preoperative MRI. In middle rectum, the anatomical analysis showed that the maximal mesorectal thickness was 60 and 20 mm posteriorly and anteriorly, respectively. In low rectum, the mesorectum was very thin and its maximal thickness was less than 10 mm anteriorly and posteriorly in all cases. The mesorectal involvement was less than 2 mm in 23% of cases. In terms of mesorectal involvement, there was good agreement between anatomical analysis and MRI for middle rectum. In contrast, the agreement was fair for low rectum. This anatomical analysis could explain the poor performance of MRI in the assessement of mesorectum involvement in low rectum.

Adipose Tissue↗
PubMed2004

Loss of heterozygosity on 10q and mutational status of PTEN and BMPR1A in colorectal primary tumours and metastases.

We investigated the possible role of chromosome 10q losses in colorectal cancer metastasis by carrying out an allelic imbalance study on a series of microsatellite instability-negative (MSI-) primary tumours (n=32) and metastases (n=36) from 49 patients. Our results demonstrate that 10q allelic losses are associated with a significant proportion (25%) of MSI- colorectal tumours, but are not involved in the metastatic process. PTEN and BMPR1A, two genes located in the common deleted region, were screened for mutations in samples with loss of heterozygosity. The absence or low frequency of mutations indicates that the inactivation of these genes by deletion of one allele and mutation of the other one plays only a minor role in MSI- tumours.

Base Sequence↗
PubMed2004

Endothelial cytochrome P450 contributes to the acetylcholine-induced cardiodepression in isolated rat hearts.

AIMS: Acetylcholine (ACh) is known to reduce the contractility of the heart by acting on myocardial muscarinic M2 receptors. ACh induces also an endothelial-dependent vasodilatation by causing the release of nitric oxide (NO), prostacyclin and endothelium-derived hyperpolarizing factors from the vascular endothelium. It has been proposed that ACh elicits a hyperpolarization of the coronary endothelial cells which may be accompanied by the activation of cytochrome P450 (CYP) and the resulting release of epoxyeicosatrienoic acids (EETs). The study aims at investigating whether endothelial CYP is involved in the cardiodepression by ACh. METHODS AND RESULTS: In isolated rat hearts, cardiodepression by ACh (i.e. 25-30% reduction of developed left ventricular pressure) was partially attenuated either by inhibition of CYP with 1-aminobenzotriazole (ABT) or by endothelial dysfunction obtained with Triton X-100. No attenuation of cardiodepression was seen after nitric oxide synthase and cyclooxygenase inhibition by L-nitro-arginine methyl ester and indomethacin, respectively. CONCLUSION: The results suggest that the negative inotropic effect of ACh depends not only on a direct myocardial effect but also on the endothelial CYP activation.

Acetylcholine↗
PubMed2003

Surgery and local treatments of liver metastases from colorectal cancer: how to improve results.

Over the last 30 years, the benefits of surgical resection for liver metastases have been established. Actually, surgical resections are feasible with a very low mortality and a 5-year survival that approaches 40 %. However, even if progresses in surgery and anaesthesiology now render possible extensive resections with removal of large, numerous or bilateral lesions, only 10 to 20 % of patients are candidate to surgery. The others gain benefit from chemotherapy with more and more active drugs. To improve this overall picture, efforts have been made to increase the number of patients that could be candidates for surgery. Shrinkage of tumours after administration of preoperative chemotherapy and availability of ablative techniques now permit to treat with curative intent metastases initially considered as non-resectable.

Catheter Ablation↗
PubMed2002

Fatty acids are important for the Frank-Starling mechanism and Gregg effect but not for catecholamine response in isolated rat hearts.

In some pathophysiological conditions myocardial metabolism can switch from mainly long chain fatty acid (LCFA) oxidation to mainly glucose oxidation. Whether the predominant fatty acid or glucose oxidation affects cardiac performance has not been defined. In a buffer perfused isovolumetrically contracting rat heart, oxidation of endogenous pool LCFA was avoided by inhibiting carnitine-palmitoyl-transferase I (CPT-I) with oxfenicine (2 mM). In order to restore fatty acid oxidation, hexanoate (1 mM), which bypasses CPT-I inhibition, was added to the perfusate. Three groups of hearts were subjected to either an increase in left ventricular volume (VV, +25%) or an increase in coronary flow (CF, +50%), or inotropic stimulation with isoproterenol (10(-8) and 10(-6) m). The increase in VV (the Frank-Starling mechanism) increased rate-pressure product (RPP) by 21 +/- 2% under control conditions, but only by 6 +/- 2% during oxfenicine-induced CPT-I inhibition. The contractile response to changes in VV recovered after the addition of hexanoate. Similar results were obtained in hearts, in which an increase in CF was elicited (the Gregg phenomenon). Isoproterenol caused a similar increase in contractility regardless of the presence of oxfenicine or hexanoate. In all groups, a commensurate increase in oxygen consumption accompanied the increase in contractility. The fatty acid oxidation is necessary for an adequate contractile response of the isolated heart to increased pre-load or flow, whereas the inotropic response to adrenergic beta-receptor stimulation is insensitive to changes in substrate availability.

Animals↗
PubMed2002

[Cervical cytologic reports of ASCUS and LSIL. Cyto-histological correlation and implication for management].

BACKGROUND: The purpose of this retrospective study is to evaluate the appropriate management of ASCUS and LSIL pap smears by correlating the histological findings obtained by punch biopsy or excised specimens. METHODS: The study group included 584 women with abnormal pap smear: 358 with ASCUS and 226 with LSIL cytological abnormalities. All patients underwent colposcopy and, if necessary, directed-punch biopsy. In case of biopsy-proven dysplasia a destructive or excisional treatment was performed, as indicated. RESULTS: The prevalence of HPV-CIN histological lesions in ASCUS patients was 36.3% and in LSIL patients was 67.7%. High grade CIN was observed in 15.7 and 20.8% respectively. In one ASCUS patients an invasive lesion was diagnosed on punch biopsy and two LSIL patients showed stromal invasion on the final histopathologic report on excised specimens. CONCLUSIONS: Patients with ASCUS or LSIL pap smear exhibit a wide spectrum of histological findings ranging from no pathologic abnormality to frequent high grade CIN and invasive carcinoma in rare cases. Because of the histological assessment by directed-punch biopsy and its therapeutical indications, colposcopic examination is recommended for all women with a cytologic diagnosis of ASCUS and LSIL.

Adolescent↗
PubMed2002

[Cervical myomectomy by laser CO2. Report of two cases].

Cervical localization of uterine fibroids is an uncommon event and vaginal surgery by cold knife is the current therapeutic approach. Two patients with cervical fibroids underwent laser CO2 excision under colposcopic guidance, using local anesthesia and in outpatient setting. The absence of intra- and post-surgical complications and the successful therapeutical results prove that laser CO2 surgery could be an alternative treatment in selected cases.

Carbon Dioxide↗
PubMed2001

No evidence of somatic FGFR3 mutation in various types of carcinoma.

Germline specific point mutations in the gene encoding fibroblast growth factor receptor 3 (FGFR3) are associated with autosomal dominant human skeletal dysplasia and craniosynostosis syndromes. Mutations identical to the germinal activating mutations found in severe skeletal dysplasias have been identified in certain types of cancer: at low frequency in multiple myeloma and cervix carcinoma and at high frequency in bladder carcinoma. We analysed, by SSCP and sequencing, the prevalence of FGFR3 mutations in 116 primary tumours of various types (upper aerodigestive tract, oesophagus, stomach, lung and skin). The regions analysed encompassed all FGFR3 point mutations previously described in severe skeletal dysplasia and cancers. No mutations were detected in the tumour types examined, suggesting that FGFR3 mutations are restricted to a few tumour types, the evidence to date suggesting that they are very specific to bladder carcinomas.

Bone Diseases, Developmental↗
PubMed2001

Comparison between the effects of pentobarbital or ketamine/nitrous oxide anesthesia on metabolic and endothelial components of coronary reactive hyperemia.

Barbiturates induce reduction of myocardial contractility and metabolism, whereas ketamine exerts a sympathomimetic effect that can mask its direct depressant effect on contractility. However, it is unclear whether barbiturates, which interfere with the cytochrome P-450 pathway, or ketamine, which inhibits nitric oxide synthesis, also alter the responsiveness of the coronary vessels to vasodilator stimuli. We hypothesized that the parameters of coronary reactive hyperemia (CRH), which reflect both the degree of myocardial metabolism and vascular reactivity, could be modified by the type of anesthesia used. In two groups of goats, anesthesia was induced either using ketamine plus nitrous oxide or pentobarbital alone. To record coronary flow an electromagnetic flow-probe was placed around the left circumflex coronary artery. In the ketamine group (n = 14) and in the pentobarbital group (n = 16) CRH was studied using the indices of myocardial metabolism and vascular dilator responsiveness. In the pentobarbital group all of the indices of myocardial metabolism were lower than in the ketamine group (i.e. the excess to debt flow ratio was 2.3+/-0.8 vs. 4.6+/-2.4; p< 0.001). Yet, some indices of vascular responsiveness (time derivative of coronary flow and the peak to basal flow ratio) were not different in the two groups. Moreover, the duration of the reactive hyperemia was shorter in the ketamine than in the pentobarbital group (118+/-47 vs. 153+/-45 s, p<0.05). It is suggested that pentobarbital decreases the indices of CRH related to metabolic activity, whereas ketamine reduces the duration of the hyperemic response, which suggests an impairment of endothelial function.

Anesthesia↗
PubMed2001

Antimicrobial activity of Argentine plants used in the treatment of infectious diseases. Isolation of active compounds from Sebastiania brasiliensis.

Different extracts of Sebastiania brasiliensis, Sebastiania klotszchiana, Polygonum punctatum, Lithraea molleoides and Myrcianthes cisplatensis, all plants growing in Entre Ríos Province and traditionally used as antiseptics, were tested against a set of Gram positive and Gram negative bacteria and fungi. All the species, with the exception of M. cisplatensis, presented activity against some of the microorganisms tested. A 50% hydroalcoholic extract of S. brasiliensis was selected for bioguided fractionation. Two antimicrobial compounds identified as methylgallate (MIC 128 microg/ml) and protocatechuic acid (MIC 128 microg/ml) were isolated apart from quercetin, kaempferol, quercitrin and gallic acid.

Anti-Bacterial Agents↗
PubMed2001

The seroepidemiology of varicella in Italy.

We conducted a seroepidemiological study to evaluate the potential impact of mass varicella vaccination on the transmission of varicella-zoster virus (VZV) in Italy, where vaccination is not mandatory. We tested 3179 serum samples, collected from September 1996 to October 1997, for specific anti-VZV antibodies using a commercially available ELISA. The results confirmed that varicella typically involves children (82.1% seroprevalence among 10- to 14-year-olds) and that the mean age of acquiring the infection seems to be increasing. The results also revealed that southern Italy, compared to the rest of the country, has a greater circulation of VZV and an earlier age of acquisition. The potential impact of mass vaccination among 12- to 18-month-old children on the epidemiological trend of the infection must be carefully considered, in that failure to reach high levels of coverage could lead to an increase in the mean age of acquisition, which is already occurring in Italy.

Adolescent↗